How to setup long distance audio connection?

[Greenie00]

Given the scenario below:

A teacher giving lesson through a mic in a lecture hall. There's a mixer/control panel at the lecturer desk where the computer, visualiser, OHP are located. A computer placed at the back of lecture hall (about 25-30m away) will be used to record the lecture voice.

Question:
How to setup the audio recording connection from front(mixer) to back(computer)?
using xlr cable? DI box?

 

[blueprintstudios]

you could have a damn ugly 35m long cable or a wireless mic setup.

 

[Greenie00]

Thought of wireless setup but will the surrounding interference affects the signal receiving? If go for cable, what other things needed and how to setup?

 

[widdly]

Why not just record on the computer at the front?

If you go for a long cable, you would want to do a balanced run. It would mean less noise and interference. Make sure you mixer at the front has a balanced output and you pc at the back has a balanced input. Make sure you are using balanced cable (XLR or TRS).

Another idea is to tap a line out of the PA somewhere. I assume the mixer at the front is fed to a PA system somewhere. You might be able to get a signal from elsewhere in the room so your cable doesn't need to be so long.

 

[Greenie00]

Thanks for all the helpful inputs.
Distance is reduced to 5m now.

mic preamp XLR output ---> female(3-hole) XLR connector ---> 5m audio cable ---> 1/8" audio jack ---> computer line-in ---> use for recording the mic signal from preamp into computer

Anyone knows will such setup as describe above works? if can't work, what can i do to record the mic from preamp to computer over 5m distance?

 

[widdly]

It will work...but it's not optimal.

The 1/8" audio jack on the computer is unbalanced so the entire 5m in your proposed setup will pick up noise.

It would be better to place the preamp next to the computer. Keep the run from the preamp to 1/8" as short as possible. Then use a good quality balanced mic cable (XLR->XLR) to run from the mic to the preamp.

 

[Greenie00]

Just realised that there's a mixer in the room. So i guess i can use the RCA out from mixer to computer line-in.

 

[Greenie00]

Today just recce on the venue again. The final setup should be from mixer stereo PHONE out(1/4") to compuer LINE-IN(3.5mm/mini jack) over about 10 to 15 meters. So what kind of cable can be used for this setup with minimum signal loss and "best" audio quality possible?